Re: Quarter-wave whip earth plane

Jasen Betts <usenet@revmaps.no-ip.org> wrote:

On 2025-03-11, Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:

Joerg <news@analogconsultants.com> wrote:

 

For example, you could get another of those hinges from a vehicle
junkyard, have someone weld a piece of steel to it and then mount the
antenna on that. If you ever sell the van you could mount the hinge you
took off.

>
I have never seen or heard of one of these being scrapped in the UK,
they are all exported to third-world counties and converted into lorries
and buses.

 
Possibly still worth a look. Rear door hinges are likely to survive a front
collision. even a rear collision. Genuine parts are also an option.

The fixing screws for those door hinges are torqued up beyond the
capabilities of any of the tools I have in my kit.  The ease of mounting
and demounting a magnetic base still appeals to me - and now I have
taken delivery of a VNA, it will be a lot easier to see where I am going
wrong and what I need to do to put it right.

Using the existing quarter-wave whip on the cooker top as my 'infinite'
plane (the weather outside is too cold to experiment on the van roof)
has already shown up the folly of a series capacitor.   I can now
separate tuning effects from feed-point impedance errors, whereas
previously I was floundering about in the dark.  I need to do a crash
course in interpreting Smith Charts.


--
~ Liz Tuddenham ~
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www.poppyrecords.co.uk